332 FORESTRY IN THE CROWN COLONIES. 



broader and slightly elevated tract composed of sand and clayey 

 soils. This belt is undulating and rising from 50 to 80 feet above 

 sea level. 



(3) The mountainous region follows the former on going west 

 and south. It contains four principal mountain ranges, of various 

 elevations, generally between 600 and 4,000 feet. The culminat- 

 ing point is reached in the flat-topped mountains Roraima and 

 Kukenaam, which rises 5,000 feet above the surrounding country 

 and 8,600 feet above sea level. The country is traversed by 

 several large rivers which, with their feeders, form a vast network 

 of waterways. All the large rivers are impeded above the tideway 

 by rapids, cataracts and falls. The easily accessible portions of 

 the Colony extend from the sea coast to these rapids, varying in 

 breadth from 35 to 110 miles, and embracing about 18,500 square 

 miles. 



Geology. — ^The alluvial deposits are of considerable depth, 

 ranging from 330 to 1 ,500 feet. They consist of marine muds and 

 sands. Residuary deposits may be seen along the courses of 

 the larger rivers, consisting mainly of arenaceous, argillaceous 

 and laterite earths arising mostly from the decomposition of 

 granite and gneiss. The residuary deposits are not infrequently 

 traversed by long ranges of sand dunes rising to 100 and even 

 200 feet in height. The rock in the rapids is gneiss, in places 

 intersected by granite. 



In the mountain region very large areas are occupied by a thick 

 formation of sandstones and conglomerates. Considerable areas 

 are occupied by schists, while gneissose rocks are found over a 

 large proportion of the country. 



Climate. — The temperature in the coastal region ranges between 

 70 and 90 degrees, the mean minimum being 74 and the mean 

 maximum 87 degrees. The temperatures in the forest regions are 

 only slightly different from those in the coastal region. In the 

 savannah tracts the range of temperature is greater than in either 

 the coast or forest region, the mean maximum being 92 and the 

 mean minimum 72 degrees. 



In the coastal region there are two wet and two dry seasons ; 

 the long wet season extends from the middle of April to August, 

 followed by a dry season which lasts to the middle of November ; 

 then comes the short wet season lasting to the end of January, 



